Sportsboards of all types, including stand-up-paddle (SUP) boards and surf boards, body boards also known as boogie boards, kite boards, windsurfers and the like, often have one or more fin boxes located on the lower side of the sportsboard into which replaceable and/or removable fins can be placed.
The standard finbox 90 as best shown in FIGS. 4 and 5A-5C comprises a central, narrow horizontal channel 92 with one or more gaps 94 which provides access to a lower internal track 96. The typical fin 60 has a small hole on one end and a pin at the other end. The upper portion 70 of the fin 60 fits into the horizontal channel 92 and the pin drops through one of the gaps 94 in the channel 92. The fin 60 can be slid forward or backward in the horizontal channel 92 and a screw driven through the small hole and into the horizontal channel 92 can be tightened into place within the horizontal channel 92 to keep the fin 60 in a fixed position underneath the sportsboard.
FIG. 4 (prior art) shows the relative angle θ of the chamferred inner surfaces 82 of the horizontal channel 92 of the standard finbox 90 used on a sportsboard 50. By providing a slight tapering of the inner surfaces 82 of the horizontal channel 92 of the standard finbox 90, the standard fin is wedged into place and seats rigidly, without having slack or spare room for wiggling, vibrating or rattling of the fin 60 during use.
One of the problems associated with securing sportsboards of all types is connecting a padlock, chain or cable to the board in order to secure it to something less portable such as a vehicle, inside a garage or other enclosure, to a tree, to a post, furniture, a dock, etc. Other than the finbox 90, a deck plug for attaching a tether typically on the upper surface of the sportsboard, and possibly one or more small hand grips placed into the sportsboard at one or more locations, there is nothing on a typical sportsboard big enough to couple a padlock or cable to. The finbox 90 would make a convenient locking location for inserting a locking device to secure the sportsboard permanently or more safely.
U.S. Pat. No. 6,691,537 issued Feb. 17, 2014 to Tan teaches a sportsboard locking device. However, while the engaging latch 62 of the engagement member 53 terminates in a foot end 57, a back pin 64 is opposite the foot end 57. Thus, when placed into the channel groove, the front foot is effectively shorter. The smaller foot end 57 on the engagement member 53 results in a locking apparatus which is less robust, less resistant to physical strain and more prone to mechanical failure. The sportsboard locking device taught by Tan is inherently subject to greater failure than the present invention as the result of rotational and/or torsional motion.
Another SUP and surf board locking device made by DockLocks of Plant City, Fla. utilizes a cleat that is placed in the horizontal channel of the finbox and screwed into place. Then, a key having expandable jaws is inserted with the jaws placed over the cleat and the key is locked into place. A typical bicycle cable can be slipped through a cable ring on top of the jaws. www.dockslocks.com
Another SUP and surf board locking device made by The Sup Lock fits into the finbox of a sportsboard. However, the apparatus requires removal of the fin prior to installation and also requires use of a special tool. http://www.thesuplock.com